Portable and collapsible boxes, pet cages, artists easels and the like are well-known in the prior art and are exemplified by what is shown in the following U.S. patents:
______________________________________ Patentee Patent No. Issue Date ______________________________________ J. H. Donaldson 1,151,671 Aug. 31, 1915 W. Cunningham 1,941,662 Jan. 2, 1934 N. Hackett 2,092,155 Sept. 7, 1937 J. J. Latura 2,410,221 Oct. 29, 1946 J. D. McKean 3,048,147 Aug. 7, 1962 J. Messeas 3,144,852 Aug. 18, 1964 H. A. Parker 3,256,860 June 21, 1966 L. E. Rogers 3,870,366 Mar. 11, 1975 A. V. Sanzone et al. 3,890,932 June 24, 1975 ______________________________________